Pathetic Telkom Mobile

For two months I am sending Telkom mobile emails to cancel my debit order as I am paying by EFT. This is the 3rd month where they apply a debit order and bank send it back. The cost every time charged by Telkom is R202.00. I have deducted this amounts from my payments because they do not answer my emails although I get case numbers every time I send them a email. Now they threaten me by sms "Dear Telkom Customer. Payment for your mobile service is overdue and will result in an interruption of your service, credit bureau listing and collection by attorneys"